The invention relates to rimless spectacles.
Such spectacles are known. In these known spectacles, the first through-hole is a circular cylindrical hole and the stud is a circular cylindrical stud. The stud is fixed in the first through-hole by gluing using an adhesive. This kind of connection between bridge and endpieces, on the one hand, and spectacle lenses, on the other hand, has proved to be sufficiently reliable. However, problems may occur when the gluing is not carried out properly. Furthermore, it has been observed that when the spectacles are treated inappropriately, the stud at the transition to the contact portion cracks or is sheared off.
The invention has the object of further developing the generic rimless spectacles in such a way that the above-mentioned problems are prevented. In particular, the spectacles to be provided shall be such that the connection between the respective spectacle lens and the bridge and/or the endpieces is always reliably firm and has a high mechanical strength even under a comparatively high strain.
According to the invention, rimless spectacles comprise two spectacle lenses, a bridge connected with both spectacle lenses, a first endpiece connected with the one of the spectacle lenses at a portion thereof facing away from the bridge, and a second endpiece connected with the other one of the spectacle lenses at a portion thereof facing away from the bridge, wherein, for connecting the bridge and/or the two endpieces with the respective spectacle lens, the latter has a first through-hole extending from the front side to the rear side thereof, and the bridge and/or each of the two endpieces has/have a contact portion abutting on the front side or the rear side of the spectacle lens as well as a stud integrally formed with the contact portion and being inserted into the first through-hole, characterized in that the first through-hole has a non-circular cross-sectional profile, that the stud has a non-circular cross-sectional profile conforming to the cross-sectional profile of the first through-hole, that in the stud and in the contact portion, a second through-hole is formed, and that a pin is inserted into the second through-hole, said pin having a head which, with its lower side, abuts on the spectacle lens on the side thereof facing away from the contact portion.
Further according to the invention, the contact portion and the stud comprise plastic material.
Further still according to the invention, each of the conforming non-circular cross-sectional profiles of the first through-hole and the stud is a profile defined by two partly overlapping circles.
Further still according to the invention, each of the conforming non-circular cross-sectional profiles of the first through-hole and the stud is a flat oval profile having straight long sides.
Further still according to the invention, a transition fit is provided between the first through-hole and the stud.
Further still according to the invention, a clearance fit is provided between the first through-hole and the stud.
Further still according to the invention, the free front surface of the stud runs flush with the side of the spectacle lens facing away from the contact portion.
Further still according to the invention, the pin is fixed in the second through-hole by a form-locking engagement.
Further still according to the invention, the pin has an external thread.
Further still according to the invention, the pin is fixed in the second through-hole by a force-locking engagement.
Further still according to the invention, the pin consists of plastic material.
Further still according to the invention, the upper side of the head of the pin is lenticular.
Further still according to the invention, the pin end facing away from the head of the pin runs flush with the surface of the contact portion facing away from the spectacle lens.
Further still according to the invention, the contact portion is arranged on the front side of the spectacle lens.
In the spectacles according to the invention, the bridge and/or the endpiece, on the one hand, and the spectacle lens, on the other hand, are firmly connected with each other without gluing being required for this purpose; thus, faulty gluing cannot have any impact on the strength of the connection. In the known spectacles, rotation prevention, i.e. the prevention of a relative rotation between bridge or endpiece and spectacle lens, is effected by the adhesive. In the spectacles according to the invention, the rotation prevention is achieved by a form-locking engagement between the stud and the first through-hole, namely in that both the first through-hole and the stud have a non-circular cross-sectional profile and these cross-sectional profiles are identical. The non-circular cross-sectional profile of the stud increases the stud""s resistance against torsion and, thus, prevents a fracture or a shearing off of the stud at the transition to the contact portion. Moreover, an advantage of the spectacles according to the invention consists in that here the function of the rotation prevention and the function of the fastening, i.e. the fixing of the bridge or the endpiece at the spectacle lens in the axial direction of the stud, are separate from each other. The last-mentioned function is effected by the pin with its head and the first-mentioned function is effected by the stud with its non-circular cross-sectional profile in interaction with the non-circular first through-hole. Thus, the prevention of rotation is ensured no matter how firmly the spectacle lens is clamped between the contact portion and the head of the stud.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawing.